pkg/http_server: move to multi-lib layout

pkg/http_server/lib/src/http_multipart_form_data_impl.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-part of http_server;
+library http_server.http_multipart_form_data_impl;
 
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
 
-class _HttpMultipartFormData extends Stream implements HttpMultipartFormData {
+import 'package:mime/mime.dart';
+
+import 'http_multipart_form_data.dart';
+
+class HttpMultipartFormDataImpl extends Stream
+    implements HttpMultipartFormData {
   final ContentType contentType;
   final HeaderValue contentDisposition;
   final HeaderValue contentTransferEncoding;
 
   final MimeMultipart _mimeMultipart;
 
   bool _isText = false;
 
   Stream _stream;
 
-  _HttpMultipartFormData(ContentType this.contentType,
+  HttpMultipartFormDataImpl(ContentType this.contentType,
                          HeaderValue this.contentDisposition,
                          HeaderValue this.contentTransferEncoding,
                          MimeMultipart this._mimeMultipart,
                          Encoding defaultEncoding) {
     _stream = _mimeMultipart;
     if (contentTransferEncoding != null) {
       // TODO(ajohnsen): Support BASE64, etc.
       throw new HttpException("Unsupported contentTransferEncoding: "
                               "${contentTransferEncoding.value}");
     }
@@ skipping 37 matching lines @@
 
         default:
           remaining[key] = multipart.headers[key];
           break;
       }
     }
     if (disposition == null) {
       throw new HttpException(
           "Mime Multipart doesn't contain a Content-Disposition header value");
     }
-    return new _HttpMultipartFormData(
+    return new HttpMultipartFormDataImpl(
         type, disposition, encoding, multipart, defaultEncoding);
   }
 
   StreamSubscription listen(void onData(data),
                             {void onDone(),
                              Function onError,
                              bool cancelOnError}) {
     return _stream.listen(onData,
                           onDone: onDone,
                           onError: onError,
                           cancelOnError: cancelOnError);
   }
 
   String value(String name) {
     return _mimeMultipart.headers[name];
   }
 }